#version 450 compatibility


layout( location = 0 ) out vec4 fFracColor;

layout( location = 1 ) uniform sampler2D m_DiffuseTex;
layout( binding = 2, r32ui) uniform uimage2D Pix;
//layout( location = 2 ) uniform sampler2D m_MaskTex;
/*layout(std140, binding = 6) buffer b_Mask {
    float m_Pix[];
};*/


in vec2 TCoord;
in vec2 MaskSize;
in vec4 vPosPos;
in vec2 rt_wh;
//in vec2 MaskTCoord;
//in vec2 Offset;

in float ParentGlobalID;
in float GlobalID;







uniform float vx_offset = 0.01;
uniform float FXAA_SPAN_MAX = 8.0;
uniform float FXAA_REDUCE_MUL = 1.0/8.0;

#define FxaaInt2 ivec2
#define FxaaFloat2 vec2
#define FxaaTexLod0(t, p) textureLod(t, p, 0.0)
#define FxaaTexOff(t, p, o, r) textureLodOffset(t, p, 0.0, o)

vec3 FxaaPixelShader(vec4 posPos, sampler2D tex, vec2 rcpFrame) // Constant {1.0/frameWidth, 1.0/frameHeight}.
{   
/*---------------------------------------------------------*/
    #define FXAA_REDUCE_MIN   (1.0/128.0)
    //#define FXAA_REDUCE_MUL   (1.0/8.0)
    //#define FXAA_SPAN_MAX     8.0
/*---------------------------------------------------------*/
    vec3 rgbNW = FxaaTexLod0(tex, posPos.zw).xyz;
    vec3 rgbNE = FxaaTexOff(tex, posPos.zw, FxaaInt2(1,0), rcpFrame.xy).xyz;
    vec3 rgbSW = FxaaTexOff(tex, posPos.zw, FxaaInt2(0,1), rcpFrame.xy).xyz;
    vec3 rgbSE = FxaaTexOff(tex, posPos.zw, FxaaInt2(1,1), rcpFrame.xy).xyz;
    vec3 rgbM  = FxaaTexLod0(tex, posPos.xy).xyz;
/*---------------------------------------------------------*/
    vec3 luma = vec3(0.299, 0.587, 0.114);
    float lumaNW = dot(rgbNW, luma);
    float lumaNE = dot(rgbNE, luma);
    float lumaSW = dot(rgbSW, luma);
    float lumaSE = dot(rgbSE, luma);
    float lumaM  = dot(rgbM,  luma);
/*---------------------------------------------------------*/
    float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
    float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
/*---------------------------------------------------------*/
    vec2 dir; 
    dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
    dir.y =  ((lumaNW + lumaSW) - (lumaNE + lumaSE));
/*---------------------------------------------------------*/
    float dirReduce = max(  (lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
    float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce);
    dir = min(FxaaFloat2( FXAA_SPAN_MAX,  FXAA_SPAN_MAX), 
          max(FxaaFloat2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX), 
          dir * rcpDirMin)) * rcpFrame.xy;
/*--------------------------------------------------------*/
    vec3 rgbA = (1.0/2.0) * (
        FxaaTexLod0(tex, posPos.xy + dir * (1.0/3.0 - 0.5)).xyz +
        FxaaTexLod0(tex, posPos.xy + dir * (2.0/3.0 - 0.5)).xyz);
    vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * (
        FxaaTexLod0(tex, posPos.xy + dir * (0.0/3.0 - 0.5)).xyz +
        FxaaTexLod0(tex, posPos.xy + dir * (3.0/3.0 - 0.5)).xyz);
    float lumaB = dot(rgbB, luma);
    if((lumaB < lumaMin) || (lumaB > lumaMax)) return rgbA;
    return rgbB; 
    
}







vec4 PostFX(sampler2D tex, vec2 uv, float time)
{
    vec4 c = vec4(0.0);
    vec2 rcpFrame = vec2(1.0/rt_wh.x, 1.0/rt_wh.y);
    c.rgb = FxaaPixelShader(vPosPos, tex, rcpFrame);
    c.a = texture2D(tex, vPosPos.xy).a;
    //c.a = 1.0;
    return c;
}



void main(){
    ivec2 coord = ivec2(gl_FragCoord.xy);
    
    fFracColor = texture(m_DiffuseTex, TCoord);
    //fFracColor = PostFX(m_DiffuseTex, TCoord, 0.0);
    
    if(int(ParentGlobalID) == 0){
        imageStore(Pix, coord, uvec4(GlobalID, GlobalID, GlobalID, GlobalID));
        
    } else {
        uvec4 z = imageLoad(Pix, coord);
        
        if(int(ParentGlobalID) == int(z.r)){
            imageStore(Pix, coord, uvec4(GlobalID, GlobalID, GlobalID, GlobalID));
            
        } else {
            fFracColor.a = 0.0;
        }

    }
    
}







